It is known in the art that .alpha.-methyl-3,4-dihydroxyphenylalaninate is useful in the treatment of antihypertensive patients (see U.S. Pat. Nos. 2,868,818 and 3,344,023). It is also known in the art that the alkyl esters of .alpha.-methyl-3,4-dihydroxyphenylalanine may be used to rapidly decrease blood pressure by parenteral administration (see U.S. Pat. No. 3,230,143). It is further known that L-.alpha.-hydrazino-.alpha.-loweralkyl-3,4-dihydroxyphenyl propionic acid or .alpha.-hydrazino-3,4-dihydroxyphenyl propionic acid potentiate the antihypertensive activity of .alpha.-methyl-3,4-dihydroxyphenylalaninate (See U.S. Pat. No. 3,462,536). It has more recently been discovered that a new class of esters of .alpha.-methyl-3,4-dihydroxyphenylalanine are particularly advantageous in combatting hypertension (see Belgium Pat. No. 820,253 published Mar. 24, 1975 or U.S. Ser. No. 482,103 filed June 25, 1974.)